Class TableGenerator
- java.lang.Object
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- org.hibernate.id.enhanced.TableGenerator
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- All Implemented Interfaces:
Serializable
,ExportableProducer
,BeforeExecutionGenerator
,Generator
,Configurable
,StandardGenerator
,IdentifierGenerator
,OptimizableGenerator
,PersistentIdentifierGenerator
public class TableGenerator extends Object implements PersistentIdentifierGenerator
An enhanced version of table-based id generation.Unlike the simplistic legacy one (which was only ever intended for subclassing support) we "segment" the table into multiple values. Thus, a single table can actually serve as the persistent storage for multiple independent generators. One approach would be to segment the values by the name of the entity for which we are performing generation, which would mean that we would have a row in the generator table for each entity name. Or any configuration really; the setup is very flexible.
By default, we use a single row for all generators (the "default" segment). The configuration parameter "prefer_entity_table_as_segment_value" can be used to change that to instead default to using a row for each entity name.
Configuration parameters Parameter name Default value Interpretation "table_name" "hibernate_sequences" The name of the table to use to store/retrieve values "value_column_name" "next_val" The name of column which holds the sequence value for the given segment "segment_column_name" "sequence_name" The name of the column which holds the segment key "segment_value" "default" The value indicating which segment is used by this generator; refers to values in the "segment_column_name" column "segment_value_length" 255 The data length of the "segment_column_name" column; used for schema creation "initial_value" 1 The initial value to be stored for the given segment "increment_size" 50 The increment size for the underlying segment; see the discussion on Optimizer
for more details."optimizer" depends on defined increment size Allows explicit definition of which optimization strategy to use - See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static String
CONFIG_PREFER_SEGMENT_PER_ENTITY
By default, in the absence of a "segment_value" setting, we use a single row for all generators.static String
DEF_SEGMENT_COLUMN
The default "segment_column_name" valuestatic int
DEF_SEGMENT_LENGTH
The default "segment_value_length" valuestatic String
DEF_SEGMENT_VALUE
The default "segment_value" value, unlessCONFIG_PREFER_SEGMENT_PER_ENTITY
is specifiedstatic String
DEF_TABLE
The default "table_name" valuestatic String
DEF_VALUE_COLUMN
The default "value_column_name" valuestatic String
SEGMENT_COLUMN_PARAM
The name of the column which holds the segment key.static String
SEGMENT_LENGTH_PARAM
Indicates the length of the column defined bySEGMENT_COLUMN_PARAM
.static String
SEGMENT_VALUE_PARAM
The value indicating which segment is used by this generator, as indicated by the actual value stored in the column indicated by "segment_column_name".static String
TABLE_PARAM
Configures the name of the table to use.static String
VALUE_COLUMN_PARAM
The name of column which holds the sequence value.-
Fields inherited from interface org.hibernate.id.IdentifierGenerator
CONTRIBUTOR_NAME, ENTITY_NAME, GENERATOR_NAME, JPA_ENTITY_NAME
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Fields inherited from interface org.hibernate.id.OptimizableGenerator
DEFAULT_INCREMENT_SIZE, DEFAULT_INITIAL_VALUE, IMPLICIT_NAME_BASE, INCREMENT_PARAM, INITIAL_PARAM, OPT_PARAM
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Fields inherited from interface org.hibernate.id.PersistentIdentifierGenerator
CATALOG, IDENTIFIER_NORMALIZER, PK, SCHEMA, TABLE, TABLES
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Constructor Summary
Constructors Constructor Description TableGenerator()
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description protected String
buildInsertQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
protected String
buildSelectQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
protected String
buildUpdateQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
void
configure(Type type, Properties parameters, ServiceRegistry serviceRegistry)
Configure this instance, given the value of parameters specified by the user as<param>
elements.protected String
determineDefaultSegmentValue(Properties params)
Used in the cases wheredetermineSegmentValue(java.util.Properties)
is unable to determine the value to use.protected QualifiedName
determineGeneratorTableName(Properties params, JdbcEnvironment jdbcEnvironment, ServiceRegistry serviceRegistry)
Determine the table name to use for the generator values.protected int
determineIncrementSize(Properties params)
protected int
determineInitialValue(Properties params)
protected String
determineSegmentColumnName(Properties params, JdbcEnvironment jdbcEnvironment)
Determine the name of the column used to indicate the segment for each row.protected int
determineSegmentColumnSize(Properties params)
Determine the size of thesegment column
protected String
determineSegmentValue(Properties params)
Determine the segment value corresponding to this generator instance.protected String
determineValueColumnName(Properties params, JdbcEnvironment jdbcEnvironment)
Determine the name of the column in which we will store the generator persistent value.Object
generate(SharedSessionContractImplementor session, Object obj)
Generate a new identifier.protected InitCommand
generateInsertInitCommand(SqlStringGenerationContext context)
String[]
getAllSqlForTests()
Deprecated.Exposed for tests only.Type
getIdentifierType()
Type mapping for the identifier.int
getIncrementSize()
The amount of increment to use.int
getInitialValue()
The initial value to use when we find no previous state in the generator table corresponding to our sequence.Optimizer
getOptimizer()
The optimizer being used by this generator.String
getSegmentColumnName()
The name of the column in which we store the segment to which each row belongs.String
getSegmentValue()
The value insegment column
corresponding to this generator instance.int
getSegmentValueLength()
The size of thesegment column
in the underlying table.long
getTableAccessCount()
Getter for property 'tableAccessCount'.String
getTableName()
The name of the table in which we store this generator's persistent state.String
getValueColumnName()
The name of the column in which we store our persistent generator value.void
initialize(SqlStringGenerationContext context)
Initializes this instance, pre-generating SQL if necessary.void
registerExportables(Database database)
Register database objects used by this identifier generator, for example, a sequence or tables.-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.hibernate.generator.BeforeExecutionGenerator
generatedOnExecution
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Methods inherited from interface org.hibernate.id.Configurable
create
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Methods inherited from interface org.hibernate.generator.Generator
allowAssignedIdentifiers, generatedOnExecution, generatesOnInsert, generatesOnUpdate, generatesSometimes
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Methods inherited from interface org.hibernate.id.IdentifierGenerator
generate, getEventTypes, supportsJdbcBatchInserts
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Field Detail
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CONFIG_PREFER_SEGMENT_PER_ENTITY
public static final String CONFIG_PREFER_SEGMENT_PER_ENTITY
By default, in the absence of a "segment_value" setting, we use a single row for all generators. This setting can be used to change that to instead default to using a row for each entity name.- See Also:
- Constant Field Values
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TABLE_PARAM
public static final String TABLE_PARAM
Configures the name of the table to use. The default value is "hibernate_sequences"- See Also:
- Constant Field Values
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DEF_TABLE
public static final String DEF_TABLE
The default "table_name" value- See Also:
- Constant Field Values
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VALUE_COLUMN_PARAM
public static final String VALUE_COLUMN_PARAM
The name of column which holds the sequence value. The default value is "next_val"- See Also:
- Constant Field Values
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DEF_VALUE_COLUMN
public static final String DEF_VALUE_COLUMN
The default "value_column_name" value- See Also:
- Constant Field Values
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SEGMENT_COLUMN_PARAM
public static final String SEGMENT_COLUMN_PARAM
The name of the column which holds the segment key. The segment defines the different buckets (segments) of values currently tracked in the table. The default value is "sequence_name"- See Also:
- Constant Field Values
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DEF_SEGMENT_COLUMN
public static final String DEF_SEGMENT_COLUMN
The default "segment_column_name" value- See Also:
- Constant Field Values
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SEGMENT_VALUE_PARAM
public static final String SEGMENT_VALUE_PARAM
The value indicating which segment is used by this generator, as indicated by the actual value stored in the column indicated by "segment_column_name". The default value for setting isDEF_SEGMENT_VALUE
, although "prefer_entity_table_as_segment_value" effects the default as well.- See Also:
- Constant Field Values
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DEF_SEGMENT_VALUE
public static final String DEF_SEGMENT_VALUE
The default "segment_value" value, unlessCONFIG_PREFER_SEGMENT_PER_ENTITY
is specified- See Also:
- Constant Field Values
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SEGMENT_LENGTH_PARAM
public static final String SEGMENT_LENGTH_PARAM
Indicates the length of the column defined bySEGMENT_COLUMN_PARAM
. Used in schema export. The default value is 255- See Also:
- Constant Field Values
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DEF_SEGMENT_LENGTH
public static final int DEF_SEGMENT_LENGTH
The default "segment_value_length" value- See Also:
- Constant Field Values
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Method Detail
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getIdentifierType
public final Type getIdentifierType()
Type mapping for the identifier.- Returns:
- The identifier type mapping.
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getTableName
public final String getTableName()
The name of the table in which we store this generator's persistent state.- Returns:
- The table name.
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getSegmentColumnName
public final String getSegmentColumnName()
The name of the column in which we store the segment to which each row belongs. The value here acts as PK.- Returns:
- The segment column name
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getSegmentValue
public final String getSegmentValue()
The value insegment column
corresponding to this generator instance. In other words this value indicates the row in which this generator instance will store values.- Returns:
- The segment value for this generator instance.
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getSegmentValueLength
public final int getSegmentValueLength()
The size of thesegment column
in the underlying table.- Returns:
- the column size.
- API Note:
- This should really have been called
segmentColumnLength
or even bettersegmentColumnSize
.
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getValueColumnName
public final String getValueColumnName()
The name of the column in which we store our persistent generator value.- Returns:
- The name of the value column.
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getInitialValue
public final int getInitialValue()
The initial value to use when we find no previous state in the generator table corresponding to our sequence.- Returns:
- The initial value to use.
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getIncrementSize
public final int getIncrementSize()
The amount of increment to use. The exact implications of this depends on the optimizer being used.- Returns:
- The increment amount.
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getOptimizer
public final Optimizer getOptimizer()
The optimizer being used by this generator.- Specified by:
getOptimizer
in interfaceOptimizableGenerator
- Returns:
- Out optimizer.
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getTableAccessCount
public final long getTableAccessCount()
Getter for property 'tableAccessCount'. Only really useful for unit test assertions.- Returns:
- Value for property 'tableAccessCount'.
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getAllSqlForTests
@Deprecated public String[] getAllSqlForTests()
Deprecated.Exposed for tests only.
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configure
public void configure(Type type, Properties parameters, ServiceRegistry serviceRegistry) throws MappingException
Description copied from interface:IdentifierGenerator
Configure this instance, given the value of parameters specified by the user as<param>
elements.This method is called just once, following instantiation, and before
IdentifierGenerator.registerExportables(Database)
.- Specified by:
configure
in interfaceConfigurable
- Specified by:
configure
in interfaceIdentifierGenerator
- Parameters:
type
- The id property type descriptorparameters
- param values, keyed by parameter nameserviceRegistry
- Access to service that may be needed.- Throws:
MappingException
- If configuration fails.
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determineGeneratorTableName
protected QualifiedName determineGeneratorTableName(Properties params, JdbcEnvironment jdbcEnvironment, ServiceRegistry serviceRegistry)
Determine the table name to use for the generator values.Called during configuration.
- Parameters:
params
- The params supplied in the generator config (plus some standard useful extras).jdbcEnvironment
- The JDBC environment- Returns:
- The table name to use.
- See Also:
getTableName()
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determineSegmentColumnName
protected String determineSegmentColumnName(Properties params, JdbcEnvironment jdbcEnvironment)
Determine the name of the column used to indicate the segment for each row. This column acts as the primary key.Called during configuration.
- Parameters:
params
- The params supplied in the generator config (plus some standard useful extras).jdbcEnvironment
- The JDBC environment- Returns:
- The name of the segment column
- See Also:
getSegmentColumnName()
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determineValueColumnName
protected String determineValueColumnName(Properties params, JdbcEnvironment jdbcEnvironment)
Determine the name of the column in which we will store the generator persistent value.Called during configuration.
- Parameters:
params
- The params supplied in the generator config (plus some standard useful extras).jdbcEnvironment
- The JDBC environment- Returns:
- The name of the value column
- See Also:
getValueColumnName()
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determineSegmentValue
protected String determineSegmentValue(Properties params)
Determine the segment value corresponding to this generator instance.Called during configuration.
- Parameters:
params
- The params supplied in the generator config (plus some standard useful extras).- Returns:
- The name of the value column
- See Also:
getSegmentValue()
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determineDefaultSegmentValue
protected String determineDefaultSegmentValue(Properties params)
Used in the cases wheredetermineSegmentValue(java.util.Properties)
is unable to determine the value to use.- Parameters:
params
- The params supplied in the generator config (plus some standard useful extras).- Returns:
- The default segment value to use.
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determineSegmentColumnSize
protected int determineSegmentColumnSize(Properties params)
Determine the size of thesegment column
Called during configuration.
- Parameters:
params
- The params supplied in the generator config (plus some standard useful extras).- Returns:
- The size of the segment column
- See Also:
getSegmentValueLength()
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determineInitialValue
protected int determineInitialValue(Properties params)
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determineIncrementSize
protected int determineIncrementSize(Properties params)
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buildSelectQuery
protected String buildSelectQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
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buildUpdateQuery
protected String buildUpdateQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
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buildInsertQuery
protected String buildInsertQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
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generateInsertInitCommand
protected InitCommand generateInsertInitCommand(SqlStringGenerationContext context)
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generate
public Object generate(SharedSessionContractImplementor session, Object obj)
Description copied from interface:IdentifierGenerator
Generate a new identifier.- Specified by:
generate
in interfaceIdentifierGenerator
- Parameters:
session
- The session from which the request originatesobj
- the entity or collection (idbag) for which the id is being generated- Returns:
- a new identifier
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registerExportables
public void registerExportables(Database database)
Description copied from interface:IdentifierGenerator
Register database objects used by this identifier generator, for example, a sequence or tables.This method is called just once, after
IdentifierGenerator.configure(Type, Properties, ServiceRegistry)
.- Specified by:
registerExportables
in interfaceExportableProducer
- Specified by:
registerExportables
in interfaceIdentifierGenerator
- Parameters:
database
- The database instance
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initialize
public void initialize(SqlStringGenerationContext context)
Description copied from interface:Configurable
Initializes this instance, pre-generating SQL if necessary.If this instance also implements
ExportableProducer
, then this method is always called afterExportableProducer.registerExportables(Database)
, and before first use.- Specified by:
initialize
in interfaceConfigurable
- Parameters:
context
- A context to help generate SQL strings
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